Target Disk Mode doesn't work, what went wrong?

Target Disk Mode is described here:

http://support.apple.com/kb/HT1661

These steps are important:

1. To hook up the Firewire cable between both machines after holding down the T key on the Target machine and waiting for its screen to show the Firewire icon. Many people try to do it after, and it doesn't work.

2. Your Mac is not capable of going into Target Disk Mode:

http://docs.info.apple.com/article.html?artnum=58606

Says which Macs can boot off Firewire drives. These are the same able to go into Target Disk Mode.

3. Note, the only G4 not able to go into Target Disk Mode is the PCI PowerMac G4 tower. Identify your G4 here:

http://docs.info.apple.com/article.html?artnum=58418

4. Macs older than 4 years may need their clock battery (a.k.a. backup battery replaced) before Target Disk Mode works. These Macs that have backup batteries are listed here:

http://docs.info.apple.com/article.html?artnum=86181

Those that don't may need their logicboard replaced if they otherwise should be able to go into Target Mode, and the original instructions don't work.

Message was edited by: a brody
This tip is ready for consideration.
Hi a brody,

1. To hook up the Firewire cable between both machines after holding down the T key on the Target machine and waiting for its screen to show the Firewire icon. Many people try to do it after, and it doesn't work.

do you mean?

1. To hook up the Firewire cable between both machines after holding down the T key on the Target machine and waiting for its screen to show the Firewire icon. Many people try to do it {color:red}before {color}, and it doesn't work.